Telegraphic receiving instrument



July M3 W23.

c. ADAMS-RANDALL TELEGRAPHIG RECEIVING INSTRUMENT Filed Sept. 27 1920 Sweets-Sheet 1 Julv M), 1923. v 'l,46fi;%&

c. ADAMS-RANDALL TELEGRAPH'IC RECEIVING INSTRUMENT Filed Sept, 2 1920 2 Sheets-Shee'ta v a I Patented July 10, 1923.

racism career TELEGRAPHIC RECEIVING INSTRUMENT.

Application filed September 27, 1920. Serial No. 412,944.

To all whom it may con cern Be it known that l. (uwnnns Aunts-Rm- DALL, a citizen oi the United S[21t8S, IPl(ling at New York, in the county ot New York and State of New York. have invented certain new and useful Improvements in TelegraphicReceiving lnstrumc'nts; and I dohereby declare the following to be a full, clear, and exact description of the invention, such as will-enable others skilled in the art to which it appcrtains to make and use the same.

This invention relates to telegraphic rcceiving instruments and has for its object t produce a device of this character which will be simple in constriwtion, comparatively inexpensive to manufacture, and more etlicientin action than those heretofore proposed.

A further object of the invention is the production of an instrument of this character which may be operated directly on the main linecircuit, without the use of the usual relay; local battery and local circuits; and which will be entirely automatic or self-adjusting, in that ,when adjusted for use upon a maximum distance circuit, It does notrequire manual readjustment if used upon fractional parts of such circuit.

With these and other objects in view, the invention consists in the novel details of construction and combination of parts more fully hereinafter disclosed and particularly pointed out in the claims.

Referring to the accompanying drawings forming a part of this spccilication, in which like numerals designate like parts in all the views: 4

Figure l is adiagrammatic vertical sectional view of an instrument made in accordance with the present invention, taken approximately on the line 1-1 of.Figure2;

Figure 215 a diagrammatic horizontal sectional viewof a portion of the parts shown in Figure 1, taken approximately on the line2-2-of said figure;

Figure 3 is a vertical sectional view of the parts shown in F igure 1, taken approximately on the line 33,of the said figure and looking in the direction of the arrows;

Figure 4 is a diagrammatic View illustrating one form of electrical circuits and connections which may be employed with this instrument; and

Figure 5 is a diagrammatic view of a' slightly modified form of circuit of wood, hard rubber, or other suitable material, to which is suitably secured a plate 2 of metal and rigid with the said plate 2 area plurality of uprights 3 arranged substantially at the corners of the said plate and supporting at their upper ends a second plate 4, as will be clear from the (lrawings- Preferably rigid with the plate 2 an electromagnet 5 comprising the coils 6 and 7, each having the pole 1 indicates a base pier-cs and 9 respectively: and associated with the said pole pieces is an armature 10 carried by and rigid with the lever 11. which is mounted upon the shaft 12 pivotally supported by the adjustable members 13 carried by the U-shaped support H, also rigid with the plate 2.

A second or auxiliary electromagnet 15 is mounted on the said plate :2 at its opposite end for a purpose to be presently described. and comprises the coils 16 and 17 having the pole pieces 18 and 19. An armature 20 is associated with these said pole pieces and is carried by a lever 21 mounted upon the shaft 22 pivoted in the adjustable members 23 also carried by-the said support 14, as will be clear from Figures 1 and 2.

The said shaft 22 also carries to one side WEQSEM of the said lever 2] a second lever 25 having an extension 26 extending downwardly and to the right, as seen in Figures 1 and 2, underneath the lever 11. The said extension 96 is provided at its end with an enlargcnicnt 27 upon which rests one end of a spiral or other con'iprcssion spring 28, the other end of which is suitably secured to the lever 11 as will readily appear from Figure 1. A suitable adjusting screw 29 provided with a lock nut 30 and adapted to control the lever 25. is screw threaded into the plate 4 (see Figures 1 and 3).

32, 33,and Ell indicate binding posts carried by the base 1; and suitably connected to the 'electromagnets 5 and 15 by wiring, not shown. The coils 6 and 7 of themagnet 5 are joined in series in the usual manner as by the wire Fig. 4, and in like 'manner the coils 16 and 17 ot' the magnet ,15 are joined in series as by the wire 36. The two sets of coils are connected to the line wires 37 and 38 in parallel, as shown in said figure, and they are thus simultaneously and substantially equally energized by the main line current impulses. v t

As will appear more fully below it delsirable to Control the effective magnetic attraction of the magnet 15 upon its armamerely shifting the magnet 15 about the screw 40 its poles will be altered with re-.

' spect to its armature'20, asshown in broken and I have shown in lines in Figure 2, and its effective magnetic attraction of the said armature thereby (ontrolled. j Y 3 In some cases it may be desirable to amplify the sounds produced by the magnet Figure 1 one form'of a device suitable for augmenting these said sounds. cured to the plate 4 provided with an en larged port1on51 having a recess, 52 in which is mounted a suitable diaphragm 53 tying device, disclosed may armature r is now adjusted, as by carrying a U-shaped member 54 and having associated with it a suitable horn 55. The

lever 11 in this case is'provided with an'upright extension 56 carrying at its upper end a pin57 adapted to contact alternately with the legs-58 and 59 of the said U-shaped member 54. Any suitable form of amplihowever, may be employed.

The operation of the device as thus far lows:

With the parts arranged substantially as shown in Figure '1, in order to obtain the proper action of the device, it is first necessary that the lever spring 28 be so adjustedas to -mo've'the armature 10 the maximum distance from its pole piecesS and 9, when the coils 6 and 7 are tie-energized. This may be readily accomplished by manips ulatln-g the ad ustmg screw 29, which controls the lever andthrough it the compression of the said spring 28. When'the desired compression ias been secured,-the armature 20 is then adjusted with" respect to its pole pieces 18 and 19, preferably So that its maximum air gap will be somewhat less than'the maximum air gap between the and its pole pieces.

The magneti'c'attraction of the magnet oscillating it about its ivot'40 in the manner above until the force of its attraction when added to the compression of the spring 28, may be just overcome by the action of the magnet 5 upon its'armature 10 in response to electric currents of the strength usually employ-' .ed on main line circuits of this character.

be attached to' the yoke 42 to facilitate the manual adjust" ment. It will be readily apparent that by part This consists of "a support se-" the spring be briefly summarized as foldisclosed,

Under normal circuit conditions the instrument will now operate in the same man- .ner as the usual main line telegraph sounder.

It frequently happens, however, that the strength of the current over the main lines varies, due to leakage or other extraneous currents passing thereover when the telegraphic impulses are being sent or interrupted, and such variation has heretofore been the cause of much trouble and delay, and many errors in instrument constructed in accordance with the present invention, however, such Variatransmission. WV-ith an tions will be automatically compensated for, since they will affect. the strength of both of the magnetsfi and 15' 'in the'same ratio. Thatis tasty if-the current strength increases, for eXamp'le,' due to extraneous or leakagecurrents, or when the instrument is in use upon a" maximum distance circuit and its 'use changed to some fractional of such circuit, or when the resistance of a circuit is changed from its maximum resistance to' some fractional part thereof, or, when the main line current strength increased from any cause, such increase will simultaneously strengthen both of the magnets 5 and 15, which, acting in'opposition to one another through their respective armatures 1O and-20, levers 11, .21, and 25, and

28, will produce a uniform/magnetic action of the instrument, the increased magnetic action of the magnet 15 compensating the increased magnetic action of the magnet 5, whereby sharp, clear, distinct sounds or clicks are produced by the armature 10 and f hanging or clinging of the armature 10 to'its magnet 51 prevented. In other words, the magnet 15 acts as an automatic regulator 'or compensator for the magnet 5, always maintaining the action of the latter substantially uniform, regardless of the varying electrical conditions of' the circuit. r

On the other hand, should the main line current strength be diminished from any cause, such diminution will simultaneously affect the strength of both of themagnets tively as before, the sounds or clicks, however, being generally reduced in loud- 5 and 15, and their action will remain rela-' mess, but .should'. the main line current strength be diminished to such a degree that the sounds or clicks are toojlow, to. be

read reliably, the main line current strength receiving apparatus.

The magnet15 is preferably, thou 11 not necessarily,'constructed solas to he s lghtly' sluggish in its action, to the end that .force exerted therebyin addition'to that of the spring 28, in opposition to the action of the magnet 5 may be slightly prolonged aftor the breaking of the circuit. thereby se-v curing a quick break of the armature 10 and eliminating the sticking? or clinging of the said armature.

For some forms of work, the usual type of anvil may be employed in connection with this instrument, in which case the base 1 and the lever 11 need only be extended a short distance to the right and the anvil secured to the said base in operative relation to the said lever in the well known manner.

It will be evident to those-skilled in the art that in lieu of the magnet 15, the lever- 25, by the action of the magnet 5, and the lever 11, can be utilized to increase the ten sion of the spring 28, proportionately to the magnetic strength of the magnet 5 and the leverage obtained with the lever Instead of the mechanical adjustment of magnet 15 for the the eliective magnetic pole upon its arma ture, any suitable means may be employed such, for example, as a variable resistance 60, connected in series with the coils of said magnet 15 as diagramn'iatically illustrated in Figure 5. In such case, of course the nlagnet need not be pivotally mounted upon the )HSC plate 2,- bilt may be rigidly secured thereto in the same manner as the magnet It is obvious that those skilled in the art may vary the details of construction as well as the arrangement of parts without depart ing from the spirit of the invention, and therefore it is not desired to be limited to the above disclosure except as may be required by the claims.

\Vhat I claim is: v

1. In a telegraphic receiving instrument, the combination of an electro-magnet; an armature for said magnet; a second electromagnet; 21 second armature for said last named magnet; separate pivots for said armatures; a vertical pivot around which said second magnet may revolve to adjust its attraction for said second armature; a spring to hold said second magnet in its new position after having been moved around said vertical pivot; a lever mounted on the pivot of said second armature; an adjusting screw for one end of said lever; and a spring located between said first named armature and the other end of said lever, substantially as described.

2. In a telegraphic receiving instrument, the combination of asound producing electromagnet; an armature associated with said magnet and adapted to be attracted thereby; a pivot for said armature; an auxiliary electromagnet' associated with said sound purpose of controlling phraginic means associated with producing magnet; an armature associated with said auxiliary magnet; an additional pivot for said last named armature; a lever associated with said last named pivot; spring connections between said,lever and said first armature; and means'associated' with said lever adapted to adjust the compression of said spring, substantially as described.

3. in a telegraph receiving instrument the combination of a sound producing electromagnet adapted to be connectediwith a main line circuit; an armature with; a second electro-magnet associated with said first magnet, and in circuit therewith; an armature associated with said second magnet; means actuated by said second magnet op ng the attractive movement of the arm; are of the first magnet, and means adapted to determine the effective magnetic action of said second magnet without increasing the air-gap between the core ends of said second magnet and its armature, substantially as described. v

4:. In a telegraphic receiving instrument, the combination of a base; a sound producing electromagnet secured to said base; an armature pivotally associated with said magnet; a compensating magnet pivotally mounted upon said base; a second armature pivotally associated with said compensating magnet; a lever rigid with the pivot of said second armature and provided with an arm extending beneath said first armature; spring connections between said arm and said first armature; adjusting means as sociated with said lever; and means whereby said compensating magnet may be moved about its pivot relative to its armature, substantially as described.

5. In a telegraph receiving instrument adapted for use in a main line circuit, the combination of an electromagnet; an armature associated with said magnet and adapted to attracted thereby; a second electro-magnet responsive to the main line current and adapted to exert a force in opposition to the attractive movement of the armature of said first magnet; means associated with said second magnet to determine its efl'ective magnetic action, and diathe armature of said first magnet and coacting therewith for augmenting the sounds that may be produced by the action of said first magnet, substan-tially as described.

In testimony whereof I affix my signature.

CHARLES ADAMSRANDALL.

associated there- 

